[PAR_WIG1350]

cool, but one of the issues I see with scaling this up to frc size is that each drive unit would require 2 steering motors, on the other hand, a common shaft could be run through the robot from which all wheels are powered through chains and universal or cv joints. But still,the minimum number of motors for a robot supported entirely on its driving wheels is seven if three wheel units fed from a single motor driving a common shaft. if only two driving units are used, that drops down to five motors, but you now must support part of the robot on non-powered wheels which reduces available traction.

The greatest disadvantage would be that both the seven and five motor versions that I mentioned use only one motor for actually driving. in comparison, a six motor swerve drive configuration uses three of the six motors to drive and a four motor meccanum system uses all four motors to drive, but at reduced efficiency due to canceling vectors.

The final concern would be wear on the field and on the hemispherical wheels, the sliding motion that occurs when the wheels pivot on the gimbals would result in a lot of wear on the tread. Also, when a wheel is idling (when its axle is vertical and it is not contributing to motion) that part of the hemisphere, not to mention the carpet under, could experience accelerated aging and wear due to the friction and heating that would occur. The solution to this problem would be to use a low friction material like acetal (2009 wheel tread material) form the hemispheres' surfaces, but then you would have little to no traction. [In the video, he is driving on a slick floor which reduces this issue].

if these issues could be dealt with (if a team can devote 9 motors to drive and implement a weight transfer system to reduce high-wear interactions with the floor by unloading drive wheels while idling (pivoting could still pose issues, just have spare wheels to replace worn ones I guess), then it could be done and would likely win an award (specifically innovation in control). But the question is, who is willing to face the challenge*?






*probably not us, we tried an 'innovative' {read "complicated"} drive train in 2010, it wasn't pretty. On the other hand, watching a robot drive across the field as parts of the drive system fall out behind it leaving a trail of parts while it continues to drive is rather comical.